I am calling a PL*SQL from Unix shell script using 'sqlplus' command.

While doing so I am also passing parameters to the PL*SQL.

Is it possible to return a value from PL*SQL to the Unix shell script ?

A possible solution (for oracle) :

In your PL*SQL script (pl.sql):
set serveroutput on
BEGIN
. . .
dbms_output.put_line('RETURN_VALUE');
. . .
END

In your shell :
value=`sqlplus xx/xx @pl.sql`

The below script shows how to return values from PL/SQL block

variable a_var number
declare
var1 number;
begin
UPDATE EMPLOYEE
SET NAME = &1
WHERE EMP_ID= '&2';
var1 := SQL%ROWCOUNT;
IF var1 >= 1 THEN
:a_var := 0;
ELSE
:a_var := 1;
END IF;
end;
/
exit :a_var